CFD Simulation of Hydrodynamic and Thermal Performance of a Micro Heat Exchanger

To evaluate the performances and limitations of compact heat exchanger with micro-structured plates, CFD simulations of hydrodynamics and thermal transfers have been performed inside a commercial micro heat exchanger from IMM operated in liquid/liquid flows. The hydrodynamic results show that the flow rate distribution over the plates is rather homogeneous with some velocity gradient at the channel inlet due to inertial effect in the distributor. Fluid temperature profiles are both influenced by convective transfer in the channels and in the distributing/collecting sections and by conductive transfer through the metal wall at the plate periphery especially at low flow rates. Due to undesired heat transfer by conduction, the fraction of heat power really transferred inside the channels varies from 75 to 85% in counter current flow configuration and between 35 and 70% in co-current flow configuration. Computational results are successfully compared to 2D experimental temperature profiles measured inside the heat exchanger